Generalize to Callables Instead of Strictly Lambdas

.github/workflows/ci.yml

@@ -131,4 +131,4 @@ jobs:
 
     - name: Publish
       if: startsWith(github.event.release.tag_name, 'v')
-      uses: pypa/gh-action-pypi-publish@release/v1
+      uses: pypa/gh-action-pypi-publish@release/v1

src/smbprotocol/structure.py

@@ -3,6 +3,7 @@
 
 import copy
 import datetime
+import inspect
 import math
 import struct
 import textwrap
@@ -148,7 +149,7 @@ def __init__(self, little_endian=True, default=None, size=None):
         field_type = self.__class__.__name__
         self.little_endian = little_endian
 
-        if not (size is None or isinstance(size, int) or isinstance(size, types.LambdaType)):
+        if not (size is None or isinstance(size, int) or callable(size)):
             raise InvalidFieldDefinition(f"{field_type} size for field must be an int or None for a variable length")
         self.size = size
         self.default = default
@@ -270,7 +271,7 @@ def _get_calculated_value(self, value):
         :param value: The value to calculate/expand
         :return: The final value
         """
-        if isinstance(value, types.LambdaType):
+        if callable(value):
             expanded_value = value(self.structure)
             return self._get_calculated_value(expanded_value)
         else:
@@ -294,7 +295,7 @@ def _get_calculated_size(self, size, data):
         # is None (last field value)
         if size is None:
             return len(data)
-        elif isinstance(size, types.LambdaType):
+        elif callable(size):
             expanded_size = size(self.structure)
             return self._get_calculated_size(expanded_size, data)
         else:
@@ -309,7 +310,7 @@ def _get_struct_format(self, size, unsigned=True):
         :param size: The size as an int
         :return: The struct format specifier for the size specified
         """
-        if isinstance(size, types.LambdaType):
+        if callable(size):
             size = size(self.structure)
 
         struct_format = {1: "B", 2: "H", 4: "L", 8: "Q"}
@@ -345,7 +346,7 @@ def _pack_value(self, value):
     def _parse_value(self, value):
         if value is None:
             int_value = 0
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             int_value = value
         elif isinstance(value, bytes):
             struct_string = self._endian_prefix + self._get_struct_format(self.size, self.unsigned)
@@ -376,7 +377,7 @@ def _pack_value(self, value):
     def _parse_value(self, value):
         if value is None:
             bytes_value = b""
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             bytes_value = value
         elif isinstance(value, int):
             struct_string = self._endian_prefix + self._get_struct_format(self.size)
@@ -425,7 +426,7 @@ def __init__(self, list_count=None, list_type=BytesField(), unpack_func=None, **
             used when the list contains variable length values.
         :param kwargs: Any other kwarg to be sent to Field()
         """
-        if list_count is not None and not (isinstance(list_count, int) or isinstance(list_count, types.LambdaType)):
+        if list_count is not None and not (isinstance(list_count, int) or callable(list_count)):
             raise InvalidFieldDefinition(
                 "ListField list_count must be an int, lambda, or None for a variable list length"
             )
@@ -435,7 +436,7 @@ def __init__(self, list_count=None, list_type=BytesField(), unpack_func=None, **
             raise InvalidFieldDefinition("ListField list_type must be a Field definition")
         self.list_type = list_type
 
-        if unpack_func is not None and not isinstance(unpack_func, types.LambdaType):
+        if unpack_func is not None and not callable(unpack_func):
             raise InvalidFieldDefinition("ListField unpack_func must be a lambda function or None")
         elif unpack_func is None and (list_count is None or list_type.size is None):
             raise InvalidFieldDefinition(
@@ -456,7 +457,7 @@ def get_value(self):
         # Override default get_value() so we return a list with the actual
         # value, not the Field definition
         list_value = []
-        if isinstance(self.value, types.LambdaType):
+        if callable(self.value):
             value = self._get_calculated_value(self.value)
         else:
             value = self.value
@@ -474,9 +475,9 @@ def _pack_value(self, value):
     def _parse_value(self, value):
         if value is None:
             list_value = []
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             return value
-        elif isinstance(value, bytes) and isinstance(self.unpack_func, types.LambdaType):
+        elif isinstance(value, bytes) and callable(self.unpack_func):
             # use the lambda function to parse the bytes to a list
             list_value = self.unpack_func(self.structure, value)
         elif isinstance(value, bytes):
@@ -527,7 +528,7 @@ def _to_string(self):
 
     def _create_list_from_bytes(self, list_count, list_type, value):
         # calculate the list_count and rerun method if a lambda
-        if isinstance(list_count, types.LambdaType):
+        if callable(list_count):
             list_count = list_count(self.structure)
             return self._create_list_from_bytes(list_count, list_type, value)
 
@@ -576,7 +577,7 @@ def _pack_value(self, value):
     def _parse_value(self, value):
         if value is None:
             structure_value = b""
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             structure_value = value
         elif isinstance(value, bytes):
             structure_value = value
@@ -586,7 +587,7 @@ def _parse_value(self, value):
             raise TypeError(f"Cannot parse value for field {self.name} of type {type(value).__name__} to a structure")
 
         if isinstance(structure_value, bytes) and self.structure_type and structure_value != b"":
-            if isinstance(self.structure_type, types.LambdaType):
+            if callable(self.structure_type) and not inspect.isclass(self.structure_type):
                 structure_type = self.structure_type(self.structure)
             else:
                 structure_type = self.structure_type
@@ -650,7 +651,7 @@ def _pack_value(self, value):
     def _parse_value(self, value):
         if value is None:
             datetime_value = datetime.datetime.today()
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             datetime_value = value
         elif isinstance(value, bytes):
             struct_string = self._endian_prefix + self._get_struct_format(8)
@@ -713,7 +714,7 @@ def _parse_value(self, value):
             uuid_value = uuid.UUID(int=value)
         elif isinstance(value, uuid.UUID):
             uuid_value = value
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             uuid_value = value
         else:
             raise TypeError(f"Cannot parse value for field {self.name} of type {type(value).__name__} to a uuid")
@@ -823,7 +824,7 @@ def _parse_value(self, value):
             bool_value = value
         elif isinstance(value, bytes):
             bool_value = value == b"\x01"
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             bool_value = value
         else:
             raise TypeError(f"Cannot parse value for field {self.name} of type {type(value).__name__} to a bool")
@@ -854,7 +855,7 @@ def _parse_value(self, value):
             text_value = to_text(value, encoding=self.encoding)
         elif isinstance(value, str):
             text_value = value
-        elif isinstance(value, types.LambdaType):
+        elif callable(value):
             text_value = value
         else:
             raise TypeError(f"Cannot parse value for field {self.name} of type {type(value).__name__} to a text string")